I have my R21 plumed, one return over the diff and the other over 5th gear. I have my oil cooler and my pump is in the mail. So I intend to filter the oil drawn from the drain hole through the pump and on to the cooler then back to the gearbox. This is the shortest route from the drain hole to the pump. Or I have been thinking if I place the pump after the cooler the oil temp will be lower and this must be better for the pump but the length of the system that the pump would need to draw through would be longer. Can I even draw though a cooler? I intend to mount just about the entire system below the oil level in the gearbox. I am using a Mocal type pump.

What do you guys think. Also where would I add a temp sensor? Can I put it in the fill hole and rely on oil splash to get a reading? If not where would/have you put your temp sensor? I do not want to add another bung on the cases.

What temps should I be looking for? I have a Quaife LSD.

Any pictures of your mounting system and location of pumps coolers etc. would be of help.

I have mine thought out in my mind. Not plumbed yet to the trans. Need to have it dissasembled so no burrs in the case. The temp or themostat should be on the exit from the case. You need the highest temp reading. I plan on a warning lite plus a thermostat. The lite is for over temp incase levels drop or a bearing spins or worse a dropped line. To set the level you will have to prime the system to make sure the cooler is filled and there is no air in it. The type of cooler will determine how that is done. The originals used a cooler with the inflow at the bottom and exit at the top. My cooler is longer than it is tall with the ports either at the top of at the bottom. So I will have to either run longer lines to the top or have the cooler primed prior to mounting to eliminate air.
Howard, a sump pump is O K but is not a guarantee that you will keep the oil level set if you develop a leak. The level will stay there longer but eventually the level will drop if there is a big leak or a hose comes off, especially if the pump pulls from the bottom of the sump, which it shoud. You might consider a fuel level guage and sender to alert you to a low level. The fuel level guages that are offered from Pegasus and others do not use any moving parts and have a wire connection that will go to a low level light. Moroso also have several devices to warn of low oil pressure which can be plumed into the line. Here are some of the things mentioned. Several of these are wired into the ignition and will shut the ignition off if the oil pressure falls.

One of my goals is to place the temp sensor so that it will read gearbox oil temp without the pump running. I think I want to be able to turn on the pump when it is needed and after the oil has gone up to operating temp.

I intend to add the amount of oil it takes to fill the entire system, lines, pump, cooler, so that the oil volume inside of the box remains the same regardless of whether the pump is on or off. By keeping the majority of the external system below the normal gearbox oil level it should not effect the internal level much.

I was thinking something similar, but was going to use a fan thermostat switch on the trans so it would go on as needed. Then add a manual on/off overide to that. That way the common case of operation is automatic when the temp hits the trip point. In my case the 930 box does not need to have an oil pump running under normal driving, but for racing, hard driving it was told to me that it is a good idea. I would not make it more complicated then it needs to, IMHO simpler is usually better. I do like the idea of a central warning light that indicated a problem (Check Gauges Light like some cars have now). On my 930 the oil inlet to the pump comes out of the bottom of the case, so if a line break, not much can be done. And I think the ensuing fire and loss of control will be a good indication of a problem .

What size/type coolers are you folks looking at running? I was looking at one of the small fluidyne coolers (P/N DB30217) or one of the larger oil coolers in 2 pass form and mount it so fittings are up and hopefully the oil stays in the cooler when the pump is off (P/N DB30517).

I am also going to mount mine horizontally and fitting up. This is mainly for packaging but also so as not to drain the oil back into the gearbox and overfill it.

Here's a picture of mine. It is made by Earls and the Earl guy said it was just about right. "These are VERY effective coolers and most people put coolers on their car that are too big" He also said that "airflow is the main consideration anyway, put it out in cool air and you will be fine"

I intend to duct air from under the car into the cooler so I am hoping all will be well.

I am fairly sure that oil temps will be fine for road use. It's track time that I'm concerned about. I think this would be true of any gearbox.

I want to be able to watch the oil warm up as I do the first few laps and then turn on the pump to keep it cool. So I really don't need any automatic switches.

I still need a answer whether or not the side fill hole would work for a temp sensor. I'm thinking there must be a lot of oil flying around in there and the hole is right at the top of the oil level. Should be enough oil contact with the sensor to get a good reading. Right?

The Earl guy said that these coolers are many times more effective than the tube type. He said that's why they cost more.

I set up an oil cooler on my off-road buggy. I had a Medeola garbox and the fluid smelled burnt after a race. Tapped the bottom of the case drew thru a filter and used a small pump. I drew thru a filter to protect the pump. Went thru a small cooler and then into the bearing in the nose cone. We had problems with that bearing failing on early Mendeolas. The temp drop was huge. I cant remember how much but the fluid after a race did not smell and looked clean. We had no more problems with the bearing. At a later date Mendeola upgraded to a larger bearing for the fix.

Much smaller of a cooler then I expected. That is good, the smaller of the Fluidyne is the better way to go for me now that I see how big your is

The pump that came with the 930 from PowerhausII is likely that or the same one from tilton. I like the one from Weldon Engineering, but it is crazy priced.

Jim also brings up a good point, put an inline screen filter in the pickup line to the pump. I was looking at the Petersen -8 inline (for dry sump), hopefully the mesh is not too small for gearbox oil.

Howard,
That is the same cooler I am using. It has some big outlets and inlets. You will have to step it down somewhere along the line. I ordered mine large enough to fit the rear vents on either side of the exhaust. Am doing the oil that way as well. I am using the Mocal pump with mine. The spray bar setup can be had from Aircraft Spruce at:

These may be a little small. They look like the same ones in the pic. You will find that the number of holes selected in the manifold is odd to the number you want. Either plug the extra one(s), or do like I plan, and that is to cool 2nd, 3rd, 4th, and R&P. First would not be used in any racing situation, hence not needed to cool. Of course you could always make your own.
There should be enough space for air to get to the coolers unless you have the rear bottom panelled. If you duct air up into the rear clip you may have a problem with too much air pressure under the clip. Easier to add a puller fan. That way you keep air pressure to a minimum. I am including a pic of how I set mine up, and one I had a pic of. Don't remember whos ride it belongs to. I am changing the orientation of the cooler to the lines at top. Solves all air problems. once the cooler is filled it will not affect the level of the oil in the box. If the two(box and cooler) were vented to air then you would have a situation that they would seek their own common level. Since the cooler isn't it is not a problem. Your storage tank if used could be mounted anywhere. Just make entry at the bottom and exit at the top. Circulate and top off the trans to whatever level you want. Just remember with the trans flipped it does affect the fill hole or full hole (whatever??)

I am pretty sure that all these pumps are the same one with different labels. Tilton, Mocal, the one from Pegusus, and the one I found at lefthanders.

I am going to use a filter I found in Summit that has a 40 micron reusable screen and it flows at 5 gals per minute. Thats about twice the rate of the pump. The good thing is it comes with AN6 fittings.

Bill, my cooler came with AN6 fittings on it so the only thing I am going to have to use adapters on is the pump in/out. Those are really big oil coolers! They are both bigger than the one I have on my engine oil and it really works good. Oil temp is just a little higher than the water. On track I get to about 200F on the water and maybe 210F on the engine oil. 80F ish day. My engine oil cooler is mounted in front of the left side scoop. Good cool air flow there down the side of the car. If I have to I'll mount the gearbox cooler on the other side. This would really be the best location on the rear of the car but it makes the plumbing long. I don't like long oil line runs. Maybe just bring the air to the cooler and exaust it out the back.

The historic F1 cars I saw a couple of months ago had gearbox coolers on them that were 3" X 10". Mine is 6" X 4". Just about the same sq/in's

Still no answer from you guys in England about the temp sensor in the fill hole. Common..... I know you know.

Just wondering how the inline filter has performed - I have got most of the parts together now for my setup but struggling with the filter. The guy in Think Automotive in London thought that the inline mesh type filter they stock would restrict the oil flow too much as its designed for fuel. It would be ideal as you can separate the two halfs and inspect inside easily - maybe a larger mesh is available. Anybody got experience of using these ?

At this point I haven't been able to really ring the system out. The weather has been too cold to really heat anything up. So no performance data yet.
I intend to check it a couple of times a day between sessions at the first track day I attend so as not to run the pump dry with a plugged up filter.

I would however use a large capacity filter such as used on a scavenge line for a dry sump oil system. I think the small type I have used will be in danger of plugging up if it isn't inspected often.

I am holding off with a report for now because of the temp issue. The oil does flow well through the filter however when clean. I pulled off the return line to the gearbox to check flow through the system and it seamed fine.

The filter I used from Summit is below. I think the Moroso would be better. Both can be sourced form Summit

The summit one has AN6 fittings which worked perfect with my pluming scheme. The Moroso one comes in three fitting sizes, 8,10,12. It is also longer. My problem was trying to fit it all down low so as not to create drain back issues so I used the small Summit filter. It has a 3/4" diameter 80 Micron screen disk for a filter.

If it will remain flowing long enough to get through a track day (about 2 hours run time) then it will be fine. If not I'll re plumb for the moroso. It has a lot more filter area because it uses a sock type of screen filter that fills the whole filter cartridge.

By the time you are installing such a system, why do not you use it to spray oil between the pinion and the crown wheel and/or somewhere else in order to maximase the profit of the system. To me it looks a bit too much for just cooling down the lubricant.
Ciao Wanni